title: PCR for detection of herpes simplex virus in cerebrospinal fluid: alternative acceptance criteria for diagnostic workup.
abstract: The determination of herpes simplex virus (HSV) infection using a PCR assay is one of the most commonly requested tests for analysis of cerebrospinal fluid (CSF), although only a very low proportion of results are positive. A previously reported study showed that selecting only those CSF samples with >5 leukocytes/mm(3) or a protein level of >50 mg/dl was adequate for the diagnostic workup. The aim of the present study was to assess the reliability of alternative acceptance criteria based on elevated CSF white blood cell counts (>10 cells/mm(3)). We analyzed all requests for HSV PCR received between January 2008 and December 2011. CSF samples were accepted for analysis if they had >10 cells/mm(3) or if the sample was from an immunocompromised patient or a child aged <2 years. In order to evaluate our selection criteria, we identified those CSF samples with a leukocyte count of 5 to 10 cells/mm(3) or protein levels of >50 mg/dl in order to test them for HSV type 1 and 2 (HSV-1 and HSV-2) DNA. During the study period, 466 CSF samples were submitted to the microbiology laboratory for HSV PCR. Of these, 268 (57.5%) were rejected, and 198 (42.5%) were tested according to our routine criteria. Of the tested samples, 11 (5.5%) were positive for HSV DNA (7 for HSV-1 and 4 for HSV-2). Of the 268 rejected specimens, 74 met the criteria of >5 cells/mm(3) and/or protein levels of >50 mg/dl. Of these, 70 (94.6%) were available for analysis. None of the samples yielded a positive HSV PCR result. Acceptance criteria based on CSF leukocyte counts, host immune status, and age can help to streamline the application of HSV PCR without reducing sensitivity.
authors.affiliation: Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain. paulalopezroa@gmail.com
authors.forename: Paula
authors.initials: P
authors.lastname: López Roa
authors.forename: Roberto
authors.initials: R
authors.lastname: Alonso
authors.forename: Viviana
authors.initials: V
authors.lastname: de Egea
authors.forename: Rafael
authors.initials: R
authors.lastname: Usubillaga
authors.forename: Patricia
authors.initials: P
authors.lastname: Muñoz
authors.forename: Emilio
authors.initials: E
authors.lastname: Bouza
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002555:Cerebrospinal Fluid / Q000166:cytology / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D020803:Encephalitis, Herpes Simplex / Q000175:diagnosis*; D005260:Female; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000302:isolation & purification*; D018258:Herpesvirus 2, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods*; D055815:Young Adult
chemical_list: D004279:DNA, Viral